Wikenigma - an Encyclopedia of Unknowns
Wikenigma - an Encyclopedia of the Unknown
Wikenigma - an Encyclopaedia of Unknowns
Wikenigma - an Encyclopaedia of the Unknown

Mpemba effect

“Under certain conditions, it takes a shorter time to cool a hot system than to cool the same system initiated at a lower temperature. This phenomenon—the “Mpemba effect”—was first observed in water and has recently been reported in other systems. Whereas several detail-dependent explanations were suggested for some of these observations, no common underlying mechanism is known.”

There are various theories regarding an explanation of the effect, though none is yet universally accepted. Further, there is still some debate around whether the effect actually exist, or is simply due to measurement anomalies.